Offbeat, yet perfectly timed, Bock's play is a stunner -- full of intricate machinations, quirky dialogue, and monologues worthy of Durang. Characters address one person, interrupt with takes to the audience, and instantly address someone else, who may or may not be onstage. Director Nicholson manages these complicated filigrees expertly. Vincent's Nick flounces on and off the stage, briefly sets the scene, and proceeds to charm the pants off the audience, while Bales astonishes as Donna, making the play's difficult, quicksilver changes look incredibly easy. Fraser and Fairfield deftly contribute to the magic, though Fairfield sometimes lacks the required fluidity. Loopy pop songs crop up everywhere ("I Wanna Be Loved by You," the Wonder Woman TV theme, the B-52's, a James Bond underwater refrain, and more), wonderfully excerpted by sound designer Richard J. Silberg. Alex Lopez's enchanted lighting transforms Michael Frasinelli's simple set into an aquarium, a dump, a supermarket, and, best of all, a beach with fireworks. The Shotgun Players never break the spell Bock's play has cast; they enhance it. (Canadian Bock currently resides in the Mission, making him one of the best playwrights in the Bay Area.) In this show, love is risky, delirious, and utterly charming. Swimming in the Shallows causes a comic rapture of the deep.